Moving-magnet motor

ABSTRACT

A moving magnet motor comprising: a stationary voice coil coupled to a frame; a moving magnet assembly movably coupled to the frame and operable to move relative to the stationary coil, the moving magnet assembly comprising a magnet and a flux concentrating member that define a gap within which the stationary coil is positioned; and an actuating surface coupled to the moving magnet assembly, and wherein a movement of the moving magnet assembly drives a movement of the actuating surface along an axis of translation.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a non-provisional application of co-pending U.S.Provisional Patent Application No. 63/174,942, filed Apr. 14, 2021 andincorporated herein by reference.

FIELD

An aspect of the disclosure is directed to a moving-magnet motorincluding a moving-magnet motor having a magnet assembly that movesrelative to a coil to focus the magnetic field over the coil and reducea reverse magnetic field effect. Other aspects are also described andclaimed.

BACKGROUND

In modern consumer electronics, audio capability is playing anincreasingly larger role as improvements in digital audio signalprocessing and audio content delivery continue to happen. In thisaspect, there is a wide range of consumer electronics devices that canbenefit from improved audio performance. For instance, portable devicesthat use electro-dynamic transducers having moving motor systems canbenefit from improved performance. For example, while moving motorsystems may have the advantage of using a larger coil than non-movingmotor systems, they may be less efficient because they use an openmagnetic circuit around the magnet without a region of focused magneticfield. This in turn, results in a reverse magnetic flux passing throughthe same coil that is developing the Lorentz force to excite thediaphragm. At large excursions, there becomes no dominant flux densityover the coils, which introduces distortion as the positive and negativeLorentz forces almost cancel each other out.

SUMMARY

An aspect of the disclosure is directed to an improvement over movingmagnet motors, for example loudspeaker motors. Typically, moving magnetspeakers are designed using the stray magnetic flux density of magnetsto move the motor, which are not a part of a closed magnet circuit. Whenmagnets are used outside magnetic circuits, their ability of focusingtheir magnetic flux density is very poor. The working point of a magnetin free space is very low, therefore the magnet is also not protectedfrom demagnetization under elevated temperatures. Therefore, whenloudspeakers are built with moving magnets that do not use any guidingelements for their magnetic flux, the reverse magnetic flux also passesthrough the same coil that is developing the Lorentz force to excite thediaphragm. At large excursions, there becomes no dominant flux densityover the coils, which introduces distortion as the positive and negativeLorenz forces almost cancel out each other.

The instant disclosure therefore provides a moving magnet motor having aclosed magnet circuit configured to focus a magnetic flux density on thecoil and travel over the coil driving the movement of the actuatingsurface (e.g., a speaker diaphragm). This configuration results in areverse magnetic field that becomes very small as compared to thedominant flux density on the coil such that large excursion and lowdistortion values can be achieved. To accomplish this, one or moreradially polarized magnet(s) are positioned close to the voice coil(s)(e.g., inner and outer coils having the same winding height), and themagnetic flux lines of the magnet are concentrated with one or more fluxconcentrating member(s) made of soft magnetic material(s) (e.g., a steelmaterial) positioned along the other side of the voice coil(s). Thepolarized magnet(s) and the soft magnetic material(s) are part of thesame moving mass therefore the soft magnetic material follows the motionof the magnet. This moving mass is, in turn, connected to the actuatingsurface (e.g., speaker diaphragm) such that its movement drives themovement (e.g., vibration) of the actuating surface. Since the highestconcentration of flux density occurs between the soft magneticmaterial(s) and the magnet(s), the dominant magnetic flux density moveswith the moving assembly, without much degradation depending on theposition of the diaphragm. This dominant flux density region, movingover the voice coil(s), enables larger excursion of the actuatingsurface (e.g., diaphragm), without observing reverse magnetic fielddisturbance. This is because the reverse magnetic field magnitudebecomes extremely small when compared to the dominant magnetic fluxdensity between the hard and soft magnetic parts. Accordingly, a movingmagnet motor system for driving an actuating surface with largeexcursion and low distortion values can be achieved.

Representatively, in one aspect, a moving magnet motor including astationary voice coil coupled to a frame; a moving magnet assemblymovably coupled to the frame and operable to move relative to thestationary coil, the moving magnet assembly comprising a magnet and aflux concentrating member that define a gap within which the stationarycoil is positioned; and an actuating surface coupled to the movingmagnet assembly, and wherein a movement of the moving magnet assemblydrives a movement of the actuating surface along an axis of translationis provided. The stationary coil may be a continuous voice coil. Thestationary coil may be an annularly shaped voice coil and the magnet isradially inward of the voice coil and the flux concentrating member isradially outward of the voice coil. In other aspects, the fluxconcentrating member may be radially inward of the voice coil and themagnet is radially outward of the voice coil. The magnet may be aradially polarized magnet. The flux concentrating member may be a steelstructure. In other aspects, the flux concentrating member may be aradially polarized magnet. In some aspects, the flux concentratingmember is a first flux concentrating member and the moving magnetassembly further comprises a second flux concentrating member that isdirectly coupled to the magnet. In still further aspects, the stationarycoil is a first stationary voice coil, and the assembly further includesa second stationary voice coil positioned radially outward of the firststationary voice coil. In some aspects, the first stationary voice coiland the second stationary voice coil have a same direction of currentand a same orientation. In some aspects, the flux concentrating memberis positioned between the first and second stationary voice coils, andthe magnet is a first radially polarized magnet, the moving magnetassembly further comprises a second radially polarized magnet, andwherein the first radially polarized magnet is positioned radiallyinward of the first stationary voice coil and the second radiallypolarized magnet is positioned radially outward of the second stationaryvoice coil. In other aspects, the magnet is positioned between the firstand second stationary voice coils, the flux concentrating member is afirst flux concentrating member, the moving magnet assembly furthercomprises a second flux concentrating member, and wherein the first fluxconcentrating member is positioned radially inward of the firststationary voice coil and the second flux concentrating member ispositioned radially outward of the second stationary voice coil.

In another aspects, a loudspeaker magnet motor assembly including astationary portion comprising a continuous voice coil fixedly coupled toa frame; and a moving portion comprising a diaphragm and a magnetassembly movably coupled to the frame, the magnet assembly having afirst magnet member and a second magnet member operable to focus amagnetic flux density toward the continuous voice coil and translatealong the continuous voice coil to drive a movement of the diaphragmalong an axis of translation is provided. The magnet assembly may have adisplacement range along the axis of translation that is defined by aheight of the continuous voice coil. In some aspects, the first magnetmember is a radially polarized magnet and the second magnet member is asteel member that are positioned on opposite sides of the continuousvoice coil. In some aspects, the first magnetic member and the secondmagnetic member define a gap within which the continuous voice coil ispositioned. In some aspects, the moving portion further comprises athird magnet member directly attached to the first magnet member or thesecond magnet member. In still further aspects, the continuous voicecoil is a first continuous voice coil, and the stationary portionfurther comprises a second continuous voice coil. In some aspects, thesecond magnet member may be a steel structure positioned between thefirst continuous voice coil and the second continuous voice coil, themoving portion further comprises a third magnet member, and wherein thefirst magnet member and the third magnet member are positioned alongsides of the first continuous voice coil and the second continuous voicecoil opposite the second magnet member. The moving portion may furtherinclude a third magnet member, and the first magnet member, the secondmagnet member and the third magnet member are radially polarized magnetspositioned along different sides of the first continuous voice coil andthe second continuous voice coil. In still further aspects, the firstmagnet member is a radially polarized magnet positioned between thefirst continuous voice coil and the second continuous voice coil, themoving portion further comprises a third magnet member, and wherein thesecond magnet member and the third magnet member are steel structurespositioned along different sides of the first continuous voice coil andthe second continuous voice coil.

In another aspect, an electronic device includes an electronic devicehousing, a moving magnet motor coupled to the electronic device housingand an actuating surface. The moving magnet motor may include astationary voice coil and a moving magnet assembly operable to moverelative to the stationary coil. The moving magnet assembly may includea magnet and a flux concentrating member that define a gap within whichthe stationary coil is positioned. In some aspects, the moving magnetmotor is a loudspeaker moving magnet motor and the actuating surface isa loudspeaker diaphragm. In some aspects, the actuating surface is ahousing wall of the electronic device housing.

In some aspects, the moving magnet motor of any of any of the previouslydiscussed configurations may be a loudspeaker moving magnet motor or ashaker integrated within a portable electronic device.

The above summary does not include an exhaustive list of all aspects ofthe present disclosure. It is contemplated that the disclosure includesall systems and methods that can be practiced from all suitablecombinations of the various aspects summarized above, as well as thosedisclosed in the Detailed Description below and particularly pointed outin the claims filed with the application. Such combinations haveparticular advantages not specifically recited in the above summary.

BRIEF DESCRIPTION OF THE DRAWINGS

The aspects are illustrated by way of example and not by way oflimitation in the figures of the accompanying drawings in which likereferences indicate similar elements. It should be noted that referencesto “an” or “one” aspect in this disclosure are not necessarily to thesame aspect, and they mean at least one.

FIG. 1 illustrates a cross-sectional side view of one aspect of a movingmagnet motor assembly.

FIG. 2 illustrates a schematic cross-sectional side view of anotheraspect of a moving magnet motor assembly.

FIG. 3 illustrates a schematic cross-sectional side view of anotheraspect of a moving magnet motor assembly.

FIG. 4 illustrates a schematic cross-sectional side view of anotheraspect of a moving magnet motor assembly.

FIG. 5 illustrates a schematic cross-sectional side view of anotheraspect of a moving magnet motor assembly.

FIG. 6 illustrates a schematic cross-sectional side view of anotheraspect of a moving magnet motor assembly.

FIG. 7 illustrates a schematic cross-sectional side view of anotheraspect of a moving magnet motor assembly.

FIG. 8 illustrates a schematic cross-sectional side view of anotheraspect of a moving magnet motor assembly.

FIG. 9 illustrates a schematic cross-sectional side view of anotheraspect of a moving magnet motor assembly.

FIG. 10 illustrates a schematic cross-sectional side view of anotheraspect of a moving magnet motor assembly.

FIG. 11 illustrates a schematic cross-sectional side view of anotheraspect of a moving magnet motor assembly.

FIG. 12 illustrates a simplified schematic view of an electronic devicein which a transducer assembly may be implemented.

FIG. 13 illustrates a block diagram of some of the constituentcomponents of an electronic device in which a transducer assembly may beimplemented.

DETAILED DESCRIPTION

In this section we shall explain several preferred aspects of thisdisclosure with reference to the appended drawings. Whenever the shapes,relative positions and other aspects of the parts described in theaspects are not clearly defined, the scope of the disclosure is notlimited only to the parts shown, which are meant merely for the purposeof illustration. Also, while numerous details are set forth, it isunderstood that some aspects of the disclosure may be practiced withoutthese details. In other instances, well-known structures and techniqueshave not been shown in detail so as not to obscure the understanding ofthis description.

The terminology used herein is for the purpose of describing particularaspects only and is not intended to be limiting of the disclosure.Spatially relative terms, such as “beneath”, “below”, “lower”, “above”,“upper”, and the like may be used herein for ease of description todescribe one element's or feature's relationship to another element(s)or feature(s) as illustrated in the figures. It will be understood thatthe spatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” or “beneath” otherelements or features would then be oriented “above” the other elementsor features. Thus, the exemplary term “below” can encompass both anorientation of above and below. The device may be otherwise oriented(e.g., rotated 90 degrees or at other orientations) and the spatiallyrelative descriptors used herein interpreted accordingly.

As used herein, the singular forms “a”, “an”, and “the” are intended toinclude the plural forms as well, unless the context indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising” specify the presence of stated features, steps,operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, steps, operations,elements, components, and/or groups thereof

The terms “or” and “and/or” as used herein are to be interpreted asinclusive or meaning any one or any combination. Therefore, “A, B or C”or “A, B and/or C” mean “any of the following: A; B; C; A and B; A andC; B and C; A, B and C.” An exception to this definition will occur onlywhen a combination of elements, functions, steps or acts are in some wayinherently mutually exclusive.

FIG. 1 illustrates a cross-sectional view of a moving magnet motorassembly. In one aspect, assembly 100 may be, for example, a movingmagnet motor integrated within an electro-dynamic or electro-acoustictransducer that converts electrical signals into vibrations and/oraudible signals that can be output from a device within which assembly100 is integrated. For example, assembly 100 may be a loudspeaker movingmagnet motor. In another aspect, assembly 100 may be a shaker used toactuate or vibrate any type of surface or structure coupled thereto, toprovide, for example, a haptic output. For example, assembly 100 may bea loudspeaker and/or shaker integrated within a smart phone, or othersimilar portable electronic device. In some cases, assembly 100 may beattached to a surface of the device to actuate (e.g., vibrate) thesurface. Assembly 100 may be enclosed within a housing or enclosure ofthe device within which it is integrated.

Assembly 100 may generally include a frame 102, a stationary portion 104and a moving portion 106 that moves relative to the stationary portion104 and frame 102. The frame 102 may be any type of support structurethat can support components of the assembly and be used to integrate theassembly within a surrounding device (e.g., a portable electronicdevice). In some aspects, frame 102 may be part of the housing of thedevice within which assembly 100 is integrated. Stationary portion 104may, in one aspect, include one or more coil(s) 108 fixedly connected tothe frame 102. The one or more coil(s) 108 may, for example, be a voicecoil formed by a copper wire winding. The voice coil 108 may be mountedat one end to a bottom wall or side 110 of frame 102. In this aspect,the voice coil may have a winding height that runs vertically, orparallel to the z-height of assembly 100, as shown. The other end (e.g.,a top end) of the coil 108 may be free and not directly attached to anyother structure or component of the assembly 100. During operation, thecoil 108 may be energized by an electric current in a desired directionand used to drive a movement of the moving portion 106.

The moving portion 106 may include a first magnet member 112 and asecond magnet member 114 that together define a gap 116 within which thecoil 108 is positioned. The first magnet member 112 and the secondmagnet member 114 may form a closed magnetic circuit that focuses themagnetic flux density toward coil 108. In this aspect, upon applicationof an electric current to coil 108, the coil reacts to the magneticfield from the closed magnetic circuit causing the first magnet member112 and the second magnet member 114 to move or translate along an axisof translation 122, as illustrated by the arrows. The axis oftranslation 122 may, for example, be parallel to the z-axis of assembly100. In some aspects, the axis of translation 122 may be consideredrunning in an axial direction and may define an axis of symmetry ofassembly 100. In still further aspects, the axis of translation 122 maybe considered parallel to, or running in the same direction as, thewinding height of coil 108 or a height of the gap 116 defined by thefirst and second magnet members 112, 114. The first magnet member 112and second magnet member 114 are, in turn, connected to an actuatingsurface 118 that is coupled to the frame 102 by a suspension member 120.Since the first magnet member 112 and the second magnet member 114 arepart of the same moving mass, the first magnet member 112 and the secondmagnet member 114 move together and drive a movement of the actuatingsurface 118 along the axis of translation 122. Since the highestconcentration of flux density occurs between the first magnet member 112and the second magnet member 114, the dominant magnetic flux densitymoves with the moving mass, without much degradation depending on theposition of the actuating surface 118 coupled thereto. This dominantflux density region, moving over the coil 108 allows for a largerexcursion of the actuating surface 118 (e.g., diaphragm), withoutobserving reverse magnetic field disturbance as previously discussed.Accordingly, assembly 100 achieves a moving magnet motor system thatdrives an actuating surface with large excursion and low distortionvalues.

Referring now in more detail to the first magnet member 112 and thesecond magnet member 114, in some aspects, at least one of the firstmagnet member 112 and/or the second magnet member 114 may be a polarizedmagnet. The polarized magnet may be a radially polarized magnet that isorientated within the assembly such that the North and South poles arearranged radially relative to axis of translation 122. In other words,facing the left or right side as viewed in FIG. 1. In still furtheraspects, one of the first magnet member 112 or the second magnet member114 may be a flux concentrating member or structure operable to focusthe magnetic flux lines of the polarized magnet (e.g., magnet member 112or 114). Representatively, one of the first magnet member 112 or thesecond magnet member 114 may be a soft magnetic material such as a steelmaterial that is operable to focus the magnetic flux lines. For example,in one aspect, the first magnet member 112 may be a radially polarizedpermanent magnet and the second magnet member 114 may be a non-polarizedsteel member that moves with the first magnet member 112 along the coil108 to focus the magnetic flux lines toward the coil 108. In anotheraspect, the second magnet member 114 may be a radially polarized magnetand the first magnet member 112 may be a non-polarized steel member. Instill further aspects, both the first magnet member 112 and the secondmagnet member 114 may be radially polarized magnets that move along thecoil 108 to focus the magnetic flux lines. In all cases, however, atleast one of the first magnet member 112 or second magnet member 114should be a radially polarized magnet positioned along one side of coil108 and the other of the first magnet member 112 or the second magnetmember 114 should be a structure which can concentrate the magnetic fluxlines toward the coil 108 (e.g. a radially polarized magnet or a softmagnetic material such as steel).

Referring now in more detail to actuating surface 118, actuating surface118 may be, for example, a sound radiating surface such as a loudspeaker diaphragm that is caused to vibrate by the moving members 112,114, and outputs sound. In other aspects, actuating surface 118 may beany type of surface where a movement or vibration is desired. Forexample, in other aspects, the actuating surface 118 may be a wall of ahousing or enclosure, such as the enclosure of a device within whichassembly 100 is integrated, or another surface or structure that can beused to create, for example, a haptic output felt by the user. Thesuspension member 120 may be a relatively compliant structure that isstrong enough to suspend the first magnet 112, second magnet member 114and actuating surface 118 from frame 102, while also allowing each ofthese components to move relative to coil 108 and frame 102. Forexample, the first magnet member 112 and the second magnet member 114may be attached to one another by a connecting member 122 (e.g., abracket, fastener, or the like), and the actuating surface 118 and/orthe suspension member 120 may connected to the first or second member112, 114 by another connecting member 124 (e.g., a bracket, fastener orthe like).

In addition, although an assembly including a single coil 108, firstmagnet member 112 and second magnet member 114 are shown, any number ofcoils and/or magnet members are contemplated. For example, assembly 100may include a pair of coils 108, a pair of first magnet members 112and/or a pair of second magnet members 114. In addition, it iscontemplated that the coil 108, first magnet member 112 and secondmagnet member 114 may be annularly shaped components. For example, coil108, magnet member 112 and magnet member 114 may have a circular,elliptical or racetrack like shape. In this aspect, first magnet member112 may be considered an inner magnet member 112 surrounded by coil 108and second magnet member 114 may be considered an outer magnet memberthat surrounds coil 108. Said another way, first magnet member 112 maybe considered radially inward to coil 108, coil 108 may be radiallyinward to second magnet member 114 and second magnet member 114 may beradially outward to coil 108.

Various magnet member/coil configurations for assembly 100 will now bedescribed in more detail in reference to FIGS. 2-11. FIGS. 2-11illustrate cross-sectional side views of a right hand side of variousassembly configurations. It should be understood that the assembly issymmetrical therefore the left hand side (not shown) will be a mirrorimage of the right hand side illustrated in FIGS. 2-11. For example, theaxis of translation 122 shown in each of the Figures may be consideredan axis of symmetry about which the assembly is considered symmetrical.In addition, it is noted that some aspects such as the frame andactuating surface are omitted from FIGS. 2-11 for ease of illustration.The omitted aspects should, however, be understood as being included inthe complete assembly for FIGS. 2-11 as previously discussed inreference to FIG. 1.

Referring now to FIG. 2, FIG. 2 illustrates assembly 200 having astationary portion 104 including a pair of coils 208A, 208B and a movingportion 106 including a pair of first magnet members 212A, 212B and asecond magnet member 214. As previously discussed, the moving portion106 (e.g., first magnet members 212A-B and second magnet member 214)moves relative to the stationary portion 104 (e.g., coils 208A-B). Inparticular, each of the first magnet members 212A-B and second magnetmember 214 translate together along the axis of translation 122 relativeto coils 208A-B as illustrated by the arrow. The first magnet members212A-B may both be radially polarized magnets which are oriented withtheir poles in the same direction as shown. The second magnet member 214may be a flux concentrating member (e.g., a soft magnetic material suchas steel) that concentrates the magnetic flux lines 224 generated by thefirst magnet members 212A-B within a region of concentrated or focusedflux density 226. In this aspect, as the first magnet members 212A-B andsecond magnet member 214 translate together along coils 208A-B, whichare positioned within the gaps 216A, 216B formed by the magnet members,the region of focused flux density 226 also travels along the windingheight of coils 208A-B. As a result, a dominant flux density region canbe maintained along the entire height of the coils 208A-B. This, inturn, enables larger excursions of the actuating surface (e.g.,actuating surface 118) connected to the moving portion 106 withoutobserving reverse magnetic field disturbance.

Referring now in more detail to the pair of coils 208A-B, coils 208A-Bmay in some aspects be separate voice coils that each have a windingheight running parallel to the z-axis, or in a z-height direction asshown. Depending on the requirements from, for example the associatedloudspeaker, coils 208A-B can be in series or parallel with a samedirection of current so they are constructive. Both of coils 208A-Bshould have the same orientation (e.g., both coils into the plane, orboth coils out of the plane). Coils 208A-B may have the same windingheight as shown, which in some cases may be greater than a height of themagnet members of the moving portion 106 and gaps 216A-B as shown. Inother aspects, coils 208A-B may have different winding heights. Each ofcoils 208A-B may, however, be considered continuous coils in that theyhave one continuous and uninterrupted winding height, in some casesformed by a single copper wire. In other words, coils 208A-B are notformed by coil sections or segments stacked one on top of the other toachieve the desired overall height shown in the Figures. In addition, aspreviously discussed, in some aspects, coils 208A-B are annularly shapedcoils therefore coil 208A may be considered an inner coil and coil 208Bmay be considered an outer coil. Said another way coil 208A may beconsidered radially inward to coil 208B, or coil 208B may be consideredradially outward to coil 208A.

Similarly, the magnet members 212A-B and 214 of the moving portion 106may be annularly shaped members (e.g., circular, elliptical, race tracklike shape or the like). In this aspect, first magnet members 212A-B maybe considered inner and outer magnet members, respectively, and secondmagnet member 214 may be a middle magnet member between the inner andouter magnet members 212A-B. Still further, the coil gap 216A may beconsidered an inner gap formed between inner magnet member 212A andmiddle magnet member 214, and coil gap 216B may be considered an outergap formed between middle magnet member 214 and outer magnet member212B.

As previously discussed, both first magnet members 212A and 212B may beradially polarized magnets and second magnet member 214 may be a fluxconcentrating member, for example, a steel structure. Each of the firstmagnet members 212A-B and second magnet member 214 may have a sameheight (dimension along the z-axis), or may have different heights. Forexample, in another aspect, each of first magnet members 212A-B andsecond magnet member 214 may have different heights that decrease towardthe axis of translation 222 (which corresponds to the axis of symmetry).Regardless of the heights of the first and second magnet members 212A-B,214, they may be considered to have a relatively large displacementrange along the axis of translation that is equal to or less than thewinding height of the coils 208A-B. In particular, the positive magneticfield is focused over a certain area of the magnet assembly such thatwhen it moves along the coils 208A-B, it is not impacted by the reversemagnetic field (which is weaker than the focused positive magneticfield), and therefore the overall sum of magnetic field is not impacted,and hence the force from the circuitry not impacted. Thus, since themoving portion 106 carries the positive magnetic field along the entireheight of the coils 208A-B, which over powers the reverse magneticfield, a positive force occurs along the entire height of the coil thusallowing for an improved displacement range. This is in comparison toopen circuit systems without a focused magnetic flux region and which donot move along the coil and therefore they may lose force along certainregions of the coil.

Referring now to FIG. 3, FIG. 3 illustrates assembly 300, which issimilar to the previously discussed assemblies in that it includes astationary portion 104 and a moving portion 106 that moves relative tothe stationary portion 104 along the axis of translation 122. Inassembly 300, however, the stationary portion 104 includes a single coil308, and the moving portion 106 includes a single first magnet member312 and single second magnet member 314 that are connected together andmove relative to coil 308. The first magnet member 312 may be a radiallypolarized magnet positioned radially outward of the coil 308. The secondmagnet member 314 may be a flux concentrating member, for example asteel structure, positioned radially inward of the coil 308. Aspreviously discussed, second magnet member 314 concentrates the magneticflux lines 324 generated by the first magnet member 312 within a regionof concentrated or focused flux density 326. In this aspect, as thefirst magnet member 312 and second magnet member 314 translate togetheralong coil 308, which is positioned within the gaps 316 formed by themagnet members, the region of focused flux density 326 also travelsalong the winding height of coil 308. As a result, as previouslydiscussed, a dominant flux density region can be maintained along theentire height of the coil 308, and in turn, larger excursions of theactuating surface (e.g., actuating surface 118) connected to the movingportion 106 can be achieved.

Referring now to FIG. 4, FIG. 4 illustrates assembly 400, which issimilar to the previously discussed assemblies in that it includes astationary portion 104 and a moving portion 106 that moves relative tothe stationary portion 104 along the axis of translation 122. Inassembly 400, however, the stationary portion 104 includes a pair ofcoils 408A and 408B, and the moving portion 106 includes a single firstmagnet member 412 and a pair of second magnet members 414A and 414B thatare connected together (and to an actuating surface) and move relativeto coils 408A-B. The first magnet member 412 may be a radially polarizedmagnet positioned between the pair of coils 408A-B. The pair of secondmagnet members 414A-B may flux concentrating members, for example steelstructures, positioned on opposite sides of the coils 408A-B, forexample, radially inward of the coil 408A and radially outward of thecoil 408B. As previously discussed, second magnet members 414A-Bconcentrate the magnetic flux lines 424 generated by the first magnetmember 412 within a region of concentrated or focused flux density 426.In this aspect, as the first magnet member 412 and second magnet members414A-B translate together along coils 408A-B, which is positioned withinthe gaps 416A, 416B formed by the magnet members, the region of focusedflux density 426 also travels along the winding height of coils 408A-B.As a result, as previously discussed, a dominant flux density region canbe maintained along the entire height of the coils 408A-B, and in turn,larger excursions of the actuating surface (e.g., actuating surface 118)connected to the moving portion 106 can be achieved.

Referring now to FIG. 5, FIG. 5 illustrates assembly 500, which issimilar to the previously discussed assemblies in that it includes astationary portion 104 and a moving portion 106 that moves relative tothe stationary portion 104 along the axis of translation 122. Inassembly 500, however, the stationary portion 104 includes a single coil508, and the moving portion 106 includes a single first magnet member512 and a single second magnet members514 that are connected together(and to an actuating surface) and move relative to coil 508. The firstmagnet member 512 may be a radially polarized magnet positioned radiallyinward of coil 508. The second magnet member 514 may a fluxconcentrating member, for example a steel structure, positioned radiallyoutward of coil 508. As previously discussed, second magnet member 514concentrates the magnetic flux lines 524 generated by the first magnetmember 512 within a region of concentrated or focused flux density 526.In this aspect, as the first magnet member 512 and second magnet member514 translate together along coil 508, which is positioned within thegap 516 formed by the magnet members, the region of focused flux density526 also travels along the winding height of coil 508. As a result, aspreviously discussed, a dominant flux density region can be maintainedalong the entire height of the coil 508, and in turn, larger excursionsof the actuating surface (e.g., actuating surface 118) connected to themoving portion 106 can be achieved.

Referring now to FIG. 6, FIG. 6 illustrates assembly 600, which issimilar to the previously discussed assemblies in that it includes astationary portion 104 and a moving portion 106 that moves relative tothe stationary portion 104 along the axis of translation 122. Inassembly 600, however, the stationary portion 104 includes a pair ofcoils 608A and 608B, and the moving portion 106 includes three firstmagnet members 612A, 612B and 612C that are attached together (and anactuating surface) and move relative to coils 608A, 608B. The firstmagnet members 612A-C may be radially polarized magnets positioned in asame direction (e.g., North and south poles facing the same direction)between and outside of the pair of coils 608A-B. In this aspect, thefirst magnet members 612A-C act as flux concentrating members for eachother and concentrate the magnetic flux lines 624 generated by the firstmagnet member 612 within a region of concentrated or focused fluxdensity 626. In this aspect, as the first magnet members 612A-Ctranslate together along coils 608A-B, which are positioned within thegaps 616A, 616B formed by the magnet members, the region of focused fluxdensity 626 also travels along the winding height of coils 608A-B. As aresult, as previously discussed, a dominant flux density region can bemaintained along the entire height of the coils 608A-B, and in turn,larger excursions of the actuating surface (e.g., actuating surface 118)connected to the moving portion 106 can be achieved.

Referring now to FIG. 7, FIG. 7 illustrates assembly 700, which issimilar to the previously discussed assemblies in that it includes astationary portion 104 and a moving portion 106 that moves relative tothe stationary portion 104 along the axis of translation 122. Inassembly 700, however, the stationary portion 104 includes a pair ofcoils 708A and 708B, and the moving portion 106 includes a pair of firstmagnet members 712A, 712B, a single second magnet member 714 and a pairof third magnet members 730A, 730B coupled to the first magnet members712A-B that are connected together (and to an actuating surface) and allmove relative to coils 708A, 708B. The first magnet members 712A-B maybe radially polarized magnets positioned radially outward of the pair ofcoils 708A-B, and the second magnet member 714 is positioned betweencoils 708A-B. The second magnet member 714 may be a flux concentratingmember (e.g., a steel structure) that concentrate the magnetic fluxlines 724 generated by the first magnet member 712A-B within a region ofconcentrated or focused flux density 726. The third magnet members730A-B may be flux concentrating members that are directly attached tothe surfaces of the first magnet members 712A-B facing the coils 708A-B.Representatively, third magnet members 730A-B may be a soft magneticmaterial similar to the second magnet member 714, for example, a steelmaterial, that is attached to the surfaces of the first magnet members712A-B. For example, third magnet member 730A may be attached to anouter surface of the first magnet member 712A that faces coil 708A, andthird magnet member 730B may be attached to an inner surface of thefirst magnet member 712B that faces coil 708B. In this aspect, as thefirst magnet members 712A-B with third magnet members 730A-B attachedand second magnet member 714 translate together along coils 708A-B,which are positioned within the gaps 716A, 716B formed by the magnetmembers, the region of focused flux density 726 also travels along thewinding height of coils 708A-B. As a result, as previously discussed, adominant flux density region can be maintained along the entire heightof the coils 708A-B, and in turn, larger excursions of the actuatingsurface (e.g., actuating surface 118) connected to the moving portion106 can be achieved.

Referring now to FIG. 8, FIG. 8 illustrates assembly 800, which issimilar to the previously discussed assemblies in that it includes astationary portion 104 and a moving portion 106 that moves relative tothe stationary portion 104 along the axis of translation 122. Inassembly 800, however, the stationary portion 104 includes a single coil808, and the moving portion 106 includes a single first magnet member812, a single second magnet member 814 and a third magnet member 830coupled to the first magnet members 812 that are connected to oneanother (and an actuating surface) and all move relative to coil 808.The first magnet member 812 may be a radially polarized magnetpositioned radially outward of the coil 808, and the second magnetmember 814 is positioned radially inward of the coil 808. The secondmagnet member 814 may be a flux concentrating member (e.g., a steelstructure) that concentrates the magnetic flux lines 824 generated bythe first magnet member 812 within a region of concentrated or focusedflux density 826. The third magnet member 830 may be a fluxconcentrating member that is directly attached to the surface of thefirst magnet member 812 facing the coil 808. Representatively, thirdmagnet member 830 may be a soft magnetic material similar to the secondmagnet member 814, for example, a steel material, that is attached tothe surface of the first magnet members 812. For example, third magnetmember 730 may be attached to an inner surface of the first magnetmember 812 that faces coil 808. In this aspect, as the first magnetmember 812 with third magnet member 830 attached and second magnetmember 814 translate together along coil 808, which is positioned withinthe gap 816 formed by the magnet members, the region of focused fluxdensity 826 also travels along the winding height of coil 808. As aresult, as previously discussed, a dominant flux density region can bemaintained along the entire height of the coil 808, and in turn, largerexcursions of the actuating surface (e.g., actuating surface 118)connected to the moving portion 106 can be achieved.

Referring now to FIG. 9, FIG. 9 illustrates assembly 900, which issimilar to the previously discussed assemblies in that it includes astationary portion 104 and a moving portion 106 that moves relative tothe stationary portion 104 along the axis of translation 122. Inassembly 900, however, the stationary portion 104 includes a pair ofcoils 908A and 908B, and the moving portion 106 includes a pair of firstmagnet members 912A, 912B, a single second magnet member 914 and fourthird magnet members 930A, 930B, 930C and 930D coupled to each of theinner and outer surfaces of the first magnet members 912A-B that allmove relative to coils 908A, 908B. The first magnet members 912A-B maybe radially polarized magnets positioned radially outward and inward ofthe pair of coils 908A-B as shown, and the second magnet member 914 ispositioned between coils 908A-B. The second magnet member 914 may be aflux concentrating member (e.g., a steel structure) that concentrate themagnetic flux lines 924 generated by the first magnet members 912A-Bwithin a region of concentrated or focused flux density 926. The thirdmagnet members 930A-D may be flux concentrating members that aredirectly attached to the surfaces of the first magnet members 912A-B.Representatively, third magnet members 930A-D may be a soft magneticmaterial similar to the second magnet member 914, for example, a steelmaterial, that is attached to the surfaces of the first magnet members912A-B. For example, third magnet member 930A may be attached to aninner surface of the first magnet member 912A that faces a center of theassembly, third magnet member 912B may be attached to an outer surfaceof the first magnet member 912A that faces coil 908A, third magnetmember 930C may be attached to an inner surface of the first magnetmember 912B that faces coil 908B and third magnet member 930D may beattached to an outer surface of first magnet member 912B facing awayfrom coil 908B . In this aspect, as the first magnet members 912A-B withthird magnet members 930A-D attached and second magnet member 914translate together along coils 908A-B, which are positioned within thegaps 916A, 916B formed by the magnet members, the region of focused fluxdensity 926 also travels along the winding height of coils 908A-B. As aresult, as previously discussed, a dominant flux density region can bemaintained along the entire height of the coils 908A-B, and in turn,larger excursions of the actuating surface (e.g., actuating surface 118)connected to the moving portion 106 can be achieved.

Referring now to FIG. 10, FIG. 10 illustrates assembly 1000, which issimilar to the previously discussed assemblies in that it includes astationary portion 104 and a moving portion 106 that moves relative tothe stationary portion 104 along the axis of translation 122. Inassembly 1000, however, the stationary portion 104 includes a singlecoil 1008, and the moving portion 106 includes a single first magnetmember 1012, a single second magnet member 1014 and a pair of thirdmagnet members 1030A, 1030B coupled to the first magnet member 1012 thatare attached to each other (and an actuating surface) and all moverelative to coil 1008. The first magnet member 1012 may be a radiallypolarized magnet positioned radially outward of the coil 1008, and thesecond magnet member 1014 is positioned radially inward of the coil1008. The second magnet member 1014 may be a flux concentrating member(e.g., a steel structure) that concentrates the magnetic flux lines 1024generated by the first magnet member 1012 within a region ofconcentrated or focused flux density 1026. The third magnet members1030A-B may be flux concentrating members that are directly attached tothe inner and outer surfaces of the first magnet member 1012.Representatively, third magnet member 1030A-B may be soft magneticmaterials similar to the second magnet member 1014, for example, a steelmaterial, that are attached to the surfaces of the first magnet members1012. For example, third magnet member 1030A may be attached to an innersurface of the first magnet member 1012 that faces coil 1008 and thirdmagnet member 1030B may be attached to an outer surface of first magnetmember 1012 facing away from coil 1008. In this aspect, as the firstmagnet member 1012 with third magnet members 1030A-B attached and secondmagnet member 1014 translate together along coil 1008, which ispositioned within the gap 1016 formed by the magnet members, the regionof focused flux density 1026 also travels along the winding height ofcoil 1008. As a result, as previously discussed, a dominant flux densityregion can be maintained along the entire height of the coil 1008, andin turn, larger excursions of the actuating surface (e.g., actuatingsurface 118) connected to the moving portion 106 can be achieved.

Referring now to FIG. 11, FIG. 11 illustrates assembly 1100, which issimilar to the previously discussed assemblies in that it includes astationary portion 104 and a moving portion 106 that moves relative tothe stationary portion 104 along the axis of translation 122. Inassembly 1100, however, the stationary portion 104 includes a singlecoil 1108, and the moving portion 106 includes a pair of first magnetmembers 1112A, 112B and a pair of third magnet member 1130A, 1130Bcoupled to the first magnet members 1112A-B that all move relative tocoil 1108. The moving portion 106 in this aspect therefore omits thepreviously discussed second magnet member (e.g., magnet member 1014).The first magnet member 1112A may be a radially polarized magnetpositioned radially inward of the coil 1108 and the first magnet member1112B is positioned radially outward of the coil 1108. The third magnetmembers 1130A-B may be flux concentrating members (e.g., a steelstructure) attached to surfaces of the first magnet members 1112A-Bfacing coil 1108. The third magnet members 1130A-B may be fluxconcentrating members that concentrate the magnetic flux lines 1124generated by the first magnet member 1112A-B within a region ofconcentrated or focused flux density 1126. The third magnet members1130A-B may be directly attached to the surfaces of the first magnetmembers 1112A-B facing the coil 1108. Representatively, third magnetmember 1130A may be a soft magnetic material such as a steel materialthat is attached to the outer surface of the first magnet member 1112Aand third magnet member 1130B may be a soft magnetic material such as asteel material attached to the inner surface of the first magnet member1112B. In this aspect, as the first magnet members 1112A-B with thirdmagnet members 1130A-B attached translate together along coil 1108,which is positioned within the gap 1116 formed by the magnet members,the region of focused flux density 1126 also travels along the windingheight of coil 1108. As a result, as previously discussed, a dominantflux density region can be maintained along the entire height of thecoil 1108, and in turn, larger excursions of the actuating surface(e.g., actuating surface 118) connected to the moving portion 106 can beachieved.

FIG. 12 illustrates a simplified schematic perspective view of anexemplary electronic device in which a transducer assembly as describedherein, may be implemented. As illustrated in FIG. 12, the transducerassembly may be integrated within a consumer electronic device 1202 suchas a smart phone with which a user can conduct a call with a far-enduser of a communications device 1204 over a wireless communicationsnetwork; in another example, the transducer assembly may be integratedwithin the housing of a tablet computer 1206. These are just twoexamples of where the transducer assembly described herein may be used;it is contemplated, however, that the transducer assembly may be usedwith any type of electronic device, for example, a home audio system,any consumer electronics device with audio capability, or an audiosystem in a vehicle (e.g., an automobile infotainment system).

FIG. 13 illustrates a block diagram of some of the constituentcomponents of an electronic device in which the transducer assemblydisclosed herein may be implemented. Device 1300 may be any one ofseveral different types of consumer electronic devices, for example, anyof those discussed in reference to FIG. 12.

In this aspect, electronic device 1300 includes a processor 1312 thatinteracts with camera circuitry 1306, motion sensor 1304, storage 1308,memory 1314, display 1322, and user input interface 1324. Main processor1312 may also interact with communications circuitry 1302, primary powersource 1310, transducer 1318 and microphone 1320. Transducer 1318 may bea speaker and/or the transducer assembly described herein. The variouscomponents of the electronic device 1300 may be digitally interconnectedand used or managed by a software stack being executed by the processor1312. Many of the components shown or described here may be implementedas one or more dedicated hardware units and/or a programmed processor(software being executed by a processor, e.g., the processor 1312).

The processor 1312 controls the overall operation of the device 1300 byperforming some or all of the operations of one or more applications oroperating system programs implemented on the device 1300, by executinginstructions for it (software code and data) that may be found in thestorage 1308. The processor 1312 may, for example, drive the display1322 and receive user inputs through the user input interface 1324(which may be integrated with the display 1322 as part of a single,touch sensitive display panel). In addition, processor 1312 may send acurrent or signal (e.g., audio signal) to transducer 1318 to facilitateoperation of transducer 1318. Representatively, the processor 1312 maysend a current or signal to one or more components of a transducerassembly (e.g., assemblies 100-1100) to drive the componentsindependently or together. For example, the coils 108-1108 could bedriven independently by different channels on the amplifier, or togetherby the same channel, depending on the application needs.

Storage 1308 provides a relatively large amount of “permanent” datastorage, using nonvolatile solid state memory (e.g., flash storage)and/or a kinetic nonvolatile storage device (e.g., rotating magneticdisk drive). Storage 1308 may include both local storage and storagespace on a remote server. Storage 1308 may store data as well assoftware components that control and manage, at a higher level, thedifferent functions of the device 1300.

In addition to storage 1308, there may be memory 1314, also referred toas main memory or program memory, which provides relatively fast accessto stored code and data that is being executed by the processor 1312.Memory 1314 may include solid state random access memory (RAM), e.g.,static RAM or dynamic RAM. There may be one or more processors, e.g.,processor 1312, that run or execute various software programs, modules,or sets of instructions (e.g., applications) that, while storedpermanently in the storage 1308, have been transferred to the memory1314 for execution, to perform the various functions described above.

The device 1300 may include communications circuitry 1302.Communications circuitry 1302 may include components used for wired orwireless communications, such as two-way conversations and datatransfers. For example, communications circuitry 1302 may include RFcommunications circuitry that is coupled to an antenna, so that the userof the device 1300 can place or receive a call through a wirelesscommunications network. The RF communications circuitry may include a RFtransceiver and a cellular baseband processor to enable the call througha cellular network. For example, communications circuitry 1302 mayinclude Wi-Fi communications circuitry so that the user of the device1300 may place or initiate a call using voice over Internet Protocol(VOIP) connection, transfer data through a wireless local area network.

The device may include a transducer 1318. Transducer 1318 may be aspeaker and/or a transducer assembly such as that described in referenceto FIGS. 1-12. Transducer 1318 may be an electric-to-acoustic transduceror sensor that converts an electrical signal input (e.g., an aocusticinput) into a sound or vibration output. The circuitry of the speakermay be electrically connected to processor 1312 and power source 1310 tofacilitate the speaker operations as previously discussed (e.g,diaphragm displacement, etc).

The device 1300 may further include a motion sensor 1304, also referredto as an inertial sensor, that may be used to detect movement of thedevice 1300, camera circuitry 1306 that implements the digital camerafunctionality of the device 1300, and primary power source 1310, such asa built in battery, as a primary power supply.

While certain aspects have been described and shown in the accompanyingdrawings, it is to be understood that such aspects are merelyillustrative of and not restrictive on the broad disclosure, and thatthe disclosure is not limited to the specific constructions andarrangements shown and described, since various other modifications mayoccur to those of ordinary skill in the art. The description is thus tobe regarded as illustrative instead of limiting. In addition, to aid thePatent Office and any readers of any patent issued on this applicationin interpreting the claims appended hereto, applicants wish to note thatthey do not intend any of the appended claims or claim elements toinvoke 35 U.S.C. 112(f) unless the words “means for” or “step for” areexplicitly used in the particular claim.

What is claimed is:
 1. A moving magnet motor comprising: a stationaryvoice coil coupled to a frame; a moving magnet assembly movably coupledto the frame and operable to move relative to the stationary coil, themoving magnet assembly comprising a magnet and a flux concentratingmember that define a gap within which the stationary coil is positioned;and an actuating surface coupled to the moving magnet assembly, andwherein a movement of the moving magnet assembly drives a movement ofthe actuating surface along an axis of translation.
 2. The moving magnetmotor of claim 1 wherein the stationary coil is a continuous voice coil.3. The moving magnet motor of claim 1 wherein the stationary coil is anannularly shaped voice coil and the magnet is radially inward of thevoice coil and the flux concentrating member is radially outward of thevoice coil.
 4. The moving magnet motor of claim 1 wherein the stationarycoil is an annularly shaped voice coil and the flux concentrating memberis radially inward of the voice coil and the magnet is radially outwardof the voice coil.
 5. The moving magnet motor of claim 1 wherein themagnet is a radially polarized magnet.
 6. The moving magnet motor ofclaim 1 wherein the flux concentrating member is a steel structure. 7.The moving magnet motor of claim 1 wherein the flux concentrating memberis a radially polarized magnet.
 8. The moving magnet motor of claim 1wherein the flux concentrating member is a first flux concentratingmember and the moving magnet assembly further comprises a second fluxconcentrating member that is directly coupled to the magnet.
 9. Themoving magnet motor assembly of claim 1 wherein the stationary coil is afirst stationary voice coil, the assembly further comprises a secondstationary voice coil positioned radially outward of the firststationary voice coil.
 10. The moving magnet motor assembly of claim 9wherein the first stationary voice coil and the second stationary voicecoil have a same direction of current and a same orientation.
 11. Themoving magnet motor of claim 9 wherein the flux concentrating member ispositioned between the first and second stationary voice coils, and themagnet is a first radially polarized magnet, the moving magnet assemblyfurther comprises a second radially polarized magnet, and wherein thefirst radially polarized magnet is positioned radially inward of thefirst stationary voice coil and the second radially polarized magnet ispositioned radially outward of the second stationary voice coil.
 12. Themoving magnet motor of claim 9 wherein the magnet is positioned betweenthe first and second stationary voice coils, the flux concentratingmember is a first flux concentrating member, the moving magnet assemblyfurther comprises a second flux concentrating member, and wherein thefirst flux concentrating member is positioned radially inward of thefirst stationary voice coil and the second flux concentrating member ispositioned radially outward of the second stationary voice coil.
 13. Aloudspeaker magnet motor assembly comprising: a stationary portioncomprising a continuous voice coil fixedly coupled to a frame; and amoving portion comprising a diaphragm and a magnet assembly movablycoupled to the frame, the magnet assembly having a first magnet memberand a second magnet member operable to focus a magnetic flux densitytoward the continuous voice coil and translate along the continuousvoice coil to drive a movement of the diaphragm along an axis oftranslation.
 14. The loudspeaker moving magnet motor assembly of claim13 the magnet assembly has a displacement range along the axis oftranslation that is defined by a height of the continuous voice coil.15. The loudspeaker moving magnet motor assembly of claim 13 wherein thefirst magnet member is a radially polarized magnet and the second magnetmember is a steel member that are positioned on opposite sides of thecontinuous voice coil.
 16. The loudspeaker moving magnet motor assemblyof claim 13 wherein the first magnetic member and the second magneticmember define a gap within which the continuous voice coil ispositioned.
 17. The loudspeaker moving magnet motor assembly of claim 13wherein the moving portion further comprises a third magnet memberdirectly attached to the first magnet member or the second magnetmember.
 18. The loudspeaker moving magnet motor assembly of claim 13wherein the continuous voice coil is a first continuous voice coil, andthe stationary portion further comprises a second continuous voice coil.19. The loudspeaker moving magnet motor assembly of claim 18 wherein thesecond magnet member is a steel structure positioned between the firstcontinuous voice coil and the second continuous voice coil, the movingportion further comprises a third magnet member, and wherein the firstmagnet member and the third magnet member are positioned along sides ofthe first continuous voice coil and the second continuous voice coilopposite the second magnet member.
 20. The loudspeaker moving magnetmotor assembly of claim 18 wherein the moving portion further comprisesa third magnet member, and the first magnet member, the second magnetmember and the third magnet member are radially polarized magnetspositioned along different sides of the first continuous voice coil andthe second continuous voice coil.
 21. The loudspeaker moving magnetmotor assembly of claim 18 wherein the first magnet member is a radiallypolarized magnet positioned between the first continuous voice coil andthe second continuous voice coil, the moving portion further comprises athird magnet member, and wherein the second magnet member and the thirdmagnet member are steel structures positioned along different sides ofthe first continuous voice coil and the second continuous voice coil.22. An electronic device comprising: an electronic device housing; amoving magnet motor coupled to the electronic device housing, the movingmagnet motor having a stationary voice coil and a moving magnet assemblyoperable to move relative to the stationary coil, the moving magnetassembly comprising a magnet and a flux concentrating member that definea gap within which the stationary coil is positioned; and an actuatingsurface coupled to the moving magnet assembly, wherein a movement of themoving magnet assembly drives a movement of the actuating surface alongan axis of translation.
 23. The electronic device of claim 22 whereinthe moving magnet motor is a loudspeaker moving magnet motor and theactuating surface is a loudspeaker diaphragm.
 24. The electronic deviceof claim 22 wherein the actuating surface is a housing wall of theelectronic device housing.